These are not necessarily in chronological order. They are all pdf files. You can click on the names to view inline, or right click and choose "save target as" (or similar) to download to you computer and print.

• 555 how-to: Step-by-step illustrated instructions for building a basic 555 timer. Blinks an LED once per second (1Hz).
• 555 circuits: Four simple 555 circuits. Individually listed below.
  • 555 circuits-1, basic timer: One part of '555 circuits', above. Basic 1Hz timer/LED blinker.
  • 555 circuits-2, 'theremin': One part of '555 circuits', above. Use a light sensor (photocell) to change the pitch of the 555 output.
  • 555 circuits-3, heat: One part of '555 circuits', above. Use a cheap-o common diode as a screaming heat sensor.
  • 555 circuits-4, modulation: One part of '555 circuits', above. Modulate the output of a 555 with another 555.
• 555 how-to (colour): Same as the how-to above, but in glorious colour.
• 555 motor: Use the 555 to turn a motor off and on.
• 555 and relay: Using a 555 and a relay to control motor direction.

• 4017 Walking Pin Counter:
  • 4017 pinouts: Pinouts and simple description.
  • 4017 circuits: Count to 10 over and over, count to a number less than 10 over and over. Count and stop. Uses LEDs.

• 4093 NAND Gate x 4 (Schmitt Trigger):
  • 4093 pinouts: Pinouts and simple description.
  • 4093 circuits: Set/Reset flip flop. Schmitt trigger circuits: digital light sensor, light controlled motor.

• General Stuff:
• 741 pinouts: The 741 is an an IC with a single, general-purpose op amp. Pinouts and brief description.
• LM386 pinouts: A 1 watt audio amplifier. Pinouts and sample circuit.
• LM339 pinouts: An IC especially designed to be a comparator, has four of them. Pinouts and brief description.
• LM3915: Dot bar/display driver. Light up 10 LED's in sequence as input voltage rises.
• Comparator Circuits:
• Test Circuit (741 Version): Details on how comparators work, plus a test circuit.
• Light Trigger (741 Version): An adjustable light (or dark) triggered circuit with digital output.
• Audio Triggered Relay (741 Version): Use a mic or audio signal to trip a relay.
• Test Circuit (LM324 Version): Details on how comparators work, plus a test circuit.
• Light Trigger (LM324 Version): An adjustable light (or dark) triggered circuit with digital output.
• 7805 Voltage Regulator: Make 5 volts for your breadboard.

• Solid State Relays: Safely control 120VAC with ICs.
• Touch Switch: QT113 based touch switch.
• 12 Second Voice Chip (ISD1212): Record and playback up to 12" of sound.
• Latching Relay: Use this circuit to control automata. A relay and 2 limit switches toggle motor direction.